排序方式: 共有49条查询结果,搜索用时 31 毫秒
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Mandana Amiri Zahra Tofighi Ali Khodayari Abolfazl Bezaatpour Shabnam Sohrabnezhad Vladyslav Mishyn Rabah Boukherroub Sabine Szunerits 《应用有机金属化学》2020,34(10):e5871
We report a Cu-based metal–organic framework (MOF) decorated by CuO nanostructures as an efficient catalyst for the oxygen evolution reaction (OER). MIL-53(Cu) was synthesized by a hydrothermal approach using 1,4-bezenedicarboxylic acid as organic precursor and further annealed at 300°C to form CuO nanostructures on its surface. The produced electrocatalyst, CuO@MIL-53(Cu), was characterized using various techniques. Under alkaline conditions, the developed electrocatalyst exhibited an overpotential of 801 and 336 mV versus RHE at 10 and 1 mA cm−2, respectively. The reproducibility of the catalytic performance was validated using several electrodes. It was confirmed that the CuO hair-like nanostructures grown on MIL-53(Cu) using thermal treatment exhibit high OER activity, good kinetics and durability. CuO@MIL-53(Cu) is an economic noble-metal-free OER electrocatalyst. It has potential for application as anode material for sustainable energy technologies like batteries, fuel cells and water electrolysis. 相似文献
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We study the effective heat conductivity of regular arrays of perfectly conducting spheres embedded in a matrix with unit conductivity. Quasifractional approximants allow us to derive an approximate analytical solution, valid for all values of the spheres volume fraction [0, max] (max is the maximum volume fraction of a spheres). As a starting point we use a perturbation approach for 0 and an asymptotic solution for max. Three different spatial arrangements of the spheres, simple cubic, body centred and face centred cubic arrays, are considered. Results obtained give a good agreement with numerical data. 相似文献
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Volodymyr D. Khavryuchenko Oleksiy V. Khavryuchenko Vladyslav V. Lisnyak 《固体与材料科学评论》2011,36(2):47-65
This article describes the genesis of amorphous silica under high-heat conditions from SiO2 molecules through protoparticles, primary particles, and aggregates to agglomerates using vibrational spectra and quantum chemical simulations data. The impact of small molecules (water, HCl, CO2) is also discussed. The article also explains the nature of the pyrogenic silica amorphism. 相似文献
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Vladyslav Yaskin 《Mathematische Annalen》2011,349(3):647-655
A question of Barker and Larman asks whether convex bodies that contain a sphere of radius t in their interiors are uniquely determined by the volumes of sections by hyperplanes tangent to the sphere. We affirmatively
solve this problem for convex polytopes. 相似文献
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K. A. Dubrovin A. E. Zarvin V. V. Kalyada V. E. Khudozhitkov A. S. Yaskin 《Journal of Applied Mechanics and Technical Physics》2018,59(5):809-817
A possibility of using small-scale vacuum setups for experimental investigations of supersonic jets escaping from supersonic nozzles into vacuum or rarefied space is considered. Results of studying the structure of the secondary supersonic flow formed in supersonic jets with developed condensation, which is detected for the first time, are reported. The present investigations are carried out with the use of photometry and spectrometry of jets with the use of radiation excited by an electron beam; flow visualization is also performed. The results obtained in the study are analyzed; capabilities and specific features of various methods of flow registration are considered. An empirical model, which establishes the dependence between the detected secondary flow and the process of formation of large clusters in the flow, is developed and justified. 相似文献
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Oleksii M. Antypenko Sergiy I. Kovalenko Oleksandr V. Karpenko Vladyslav O. Nikitin Lyudmyla M. Antypenko 《Helvetica chimica acta》2016,99(8):621-631
Considering the frightening high level of mortality from cancer, studies of anticancer agents are vital nowadays. The 24 thioderivatives of 2‐alkyl(aryl)‐quinazolin‐4(3H)‐thiones and 20 thioderivatives of [1,2,4]triazolo[1,5‐c]quinazoline‐2‐thiones were synthesized and evaluated for preliminary in vitro anticancer activity with subsequent in silico QSAR analysis. The substance 18 had the best results inhibiting growth of eight cancer cell lines: CCRF‐CEM of leukemia; SF‐539, SNB‐75, and U251 of CNS cancer; 786, RXF393, and UO‐31 of renal cancer; and MDA‐MB‐231/ATCC of breast cancer (?31.50 – 47.41% of cell growth) with low procancer effect. Calculated QSAR‐models for CCRF‐CEM of leukemia, T‐47D and HS 578T of breast cancer, and mean cell growth demonstrated good rate of anticancer activity prediction (r2 = 0.7 – 0.8, = 0.5 – 0.7). 相似文献
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Dyachenko Alla Ischenko Olena Diyuk Vitaliy Goncharuk Olena Borysenko Mykola Mischanchuk Oleksandr Zakharova Tetiana Pryhunova Olha Sternik Dariush Lisnyak Vladyslav 《Research on Chemical Intermediates》2022,48(6):2607-2625
Research on Chemical Intermediates - Oxide Ni(80)Fe(20)/SiO2, Co(93)Fe(7)/SiO2, and Ni(19)Co(77)Fe(4)/SiO2 nanocomposites (NCs) were prepared using highly dispersed silica. It was modified by... 相似文献
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Vitaliy E. Diyuk Anna V. Vakaliuk Liudmyla M. Grishchenko Oleksandr V. Mischanchuk Dmytro V. Brazhnyk Vladyslav V. Lisnyak 《Molecular Crystals and Liquid Crystals》2020,699(1):9-19
AbstractMulti-walled carbon nanotubes (MWCNTs) have an ordered geometric structure, large specific surface area, prominent electrical conductivity, and unique mechanical properties. They are nontoxic and can be used in biomedicine. Physical and surface chemical characteristics of MWCNTs should be tuned to that required to improve certain properties and obtain a variety of functional materials. We modified the MWNTs by using the barothermal Diels-Alder reaction with dienophiles, p-benzoquinone, fumaronitrile, and maleimide, to address this issue. The prepared MWCNTs were studied by SEM-EDX, nitrogen adsorption porometry, ATR FTIR, and thermal analysis. Results showed that both separate and conjugated C?=?C bonds at the edge and outer/inner surface of walls could react with dienophiles. The grafted groups are separated by the temperature on weak (low-temperature) and strong (high-temperature) chemisorbed forms; they are detached at temperatures below and above 350?°C, correspondingly. Thermal analysis shows that up to 5% of the carbon atoms are involved in the [4?+?2] cycloaddition. The high-temperature forms of the grafted groups under extreme heating can be involved in the retro-Diels-Alder reaction that breaks six-membered rings, producing a dienophile. 相似文献
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Vladyslav A. Litovchenko Iryna M. Dovzhytska 《Central European Journal of Mathematics》2012,10(3):1084-1102
In the case of initial data belonging to a wide class of functions including distributions of Gelfand-Shilov type we establish
the correct solvability of the Cauchy problem for a new class of Shilov parabolic systems of equations with partial derivatives
with bounded smooth variable lower coefficients and nonnegative genus. We also investigate the conditions of local improvement
of the convergence of a solution of this problem to its limiting value when the time variable tends to zero. 相似文献